Saffir-Simpson scales

Hurricanes not only have names, they also have numbers. For example, hurricanes Hugo in 1989 and Andrew in 1992 were a Category 4 hurricanes, Fran in 1996 was an intense Category 3 and Camille in 1969 Category 5 monster. Hurricane Gilbert in 1988 was a Category 5 storm at peak intensity and is the strongest Atlantic tropical cyclone of record, and Hurricane Mitch in 1998 was a Category 5 storm at peak intensity over the western Caribbean.

The numbers and catgories are based on the standard scale for rating the severity of hurricanes as a measure of the damage they cause. In the early 1970s, based on their observations of numerous North Atlantic Basin hurricanes, Herbert Saffir and Robert Simpson, then the Director of the National Hurricane Center, devised two definitive relating to hurricanes: the Saffir-Simpson Hurricane Scale and the Saffir-Simpson Hurricane Damage Intensity Scale.

The Saffir-Simpson Hurricane Scale rates hurricanes from category 1 through category 5 in order of increasing intensity. Each intensity category specifies the range of conditions of four criteria: barometric (central) pressure, wind speed, storm surge, and damage potential. The Saffir-Simpson Hurricane Damage Intensity Scale, in addition to the wind speed, outlines the damage potentially possible with an associated categorized hurricane.

Large trees blown down, some structural damage to small buildings, destruction of mobile homes. Flooding of sea-level coastland 8mi (13km) or more inland. Evacuation of low-lying residences ne ar the shoreline

4

extreme

131-155

210-249

944-920

1
3-18

3.9-5.6

Severe damage to roofing materials, windows, and doors, complete destruc-tion of mobile homes. Flooding of low-lying areas as much as 6mi (10km) inland. Major damage to structures near shore d ue to battering by waves and floating debris

5

catastrophic

155-

250-

920-

18-

5.6-

Complete failure of roofs on residences and industrial buildings. Overturning/ sweeping away of small buildings. Major damage to structures less than 15ft (4.6m) a.s.l. within 1,500ft (457m) o f shore. Evacution of all residential areas on low-lying ground within 5-10mi (8-16km) of shore